Local measurement of terahertz field-induced second harmonic generation in plasma filaments

作     者：Kareem J.Garriga Francis Xi‑Cheng Zhang Kareem J.Garriga Francis;Xi-Cheng Zhang

作者机构：The Institute of OpticsUniversity of RochesterRochesterNY 14627USA 

出 版 物：《Frontiers of Optoelectronics》 (光电子前沿（英文版）)

年 卷 期：2023年第16卷第4期

页      面：135-178页

核心收录：

学科分类：070207[理学-光学] 07[理学] 0702[理学-物理学] 

基　　金：supported by the Air Force Ofce of Scientifc Research(FA9550-21-1-0389 and FA9550-21-1-0300) National Science Foundation(Grant No.ECCS-2152081) 

主　　题：Terahertz detection-Plasma characterization-Spectral characterization Single-shot detection 

摘      要：The concept of Terahertz Field-Induced Second Harmonic(TFISH)Generation is revisited to introduce a single-shot detection scheme based on third order *** specifcally on the further development of THz plasma-based sources,we begin our research by reimagining the TFISH system to serve as a direct plasma *** this work,an optical probe beam is used to mix directly with the strong ponderomotive current associated with laser-induced ionization.A four-wave mixing(FWM)process then generates a strong second-harmonic optical wave because of the mixing of the probe beam with the nonlinear current components oscillating at THz *** observed conversion efciency is high enough that for the frst time,the TFISH signal appears visible to the human *** perform spectral,spatial,and temporal analysis on the detected second-harmonic frequency and show its direct relationship to the nonlinear ***,a method to detect incoherent and coherent THz inside plasma flaments is devised using spatio-temporal *** single-shot detection confgurations are theoretically described using a combination of expanded FWM models with Kostenbauder and Gaussian *** show that the retrieved temporal traces for THz radiation from single-and twocolor laser-induced air-plasma sources match theoretical descriptions very *** temporal resolution is shown with a detection bandwidth limited only by the spatial extent of the probe laser *** detection bandwidth and temporal characterization is shown for THz radiation confned to under-dense plasma flaments induced by100 fs lasers below the relativistic intensity limit.